647929649 has 2 divisors, whose sum is σ = 647929650. Its totient is φ = 647929648.

The previous prime is 647929631. The next prime is 647929673. The reversal of 647929649 is 946929746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368371249 + 279558400 = 19193^2 + 16720^2 .

It is a cyclic number.

It is not a de Polignac number, because 647929649 - 2²⁰ = 646881073 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 647929594 and 647929603.

It is not a weakly prime, because it can be changed into another prime (647929679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323964824 + 323964825.

It is an arithmetic number, because the mean of its divisors is an integer number (323964825).

Almost surely, 2^647929649 is an apocalyptic number.

It is an amenable number.

647929649 is a deficient number, since it is larger than the sum of its proper divisors (1).

647929649 is an equidigital number, since it uses as much as digits as its factorization.

647929649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5878656, while the sum is 56.

The square root of 647929649 is about 25454.4622610653. The cubic root of 647929649 is about 865.3184250944.

The spelling of 647929649 in words is "six hundred forty-seven million, nine hundred twenty-nine thousand, six hundred forty-nine".